My aforementioned U.S. Pat. No. 6,374,558 includes a comprehensive Background of the Invention. Additional background information is set forth by U.S. Pat. No. 4,805,364, granted Feb. 21, 1989 to Robert A. Smolik; buy U.S. Pat. No. 5,127,203, granted Jul. 7, 1992 to Robert F. Paquette; by U.S. Pat. No. 5,127,760, granted Jul. 7, 1992, to Todd A. Brady; by U.S. Pat. No. 5,685,121, granted Nov. 11, 1997 Frank De Framcesco and Joseph D. Alumbo; and by U.S. Pat. No. 5,313,752, granted May 24, 1994, to Michael A. Hatzinikolas.
A problem with most of the systems disclosed by Smolik U.S. Pat. No. 4,805,364; Paquette U.S. Pat. No. 5,127,203; Brady U.S. Pat. No. 5,127,760 and DeFramesco et al. U.S. Pat. No. 5,313,752 is that the components of the systems are expensive to manufacture. Another problem of the systems disclosed by Paquette U.S. Pat. No. 5,127,203 and Brady U.S. Pat. No. 5,127,760 is that the upper frame members are weakened by the way they are constructed. An object of the present invention is to provide a construction of the frame members which renders them economical to manufacture and results in stronger upper frame members and a stronger wall structure.
As disclosed in the above identified patents, the horizontal and vertical frame members are constructed from sheet-metal and are channel shaped. The upper horizontal frame member is in the form of a downwardly opening channel member having opposite sidewalls and a web that extends between the upper edges of the sidewalls. The lower frame member is in the form of an upwardly opening channel member. It has opposite sidewalls and a web that extends between the lower edges of the sidewall. The vertical frame members (or “studs”) are also channel-shaped, except that they include also lips which extend inwardly in coplanar parallelism from the edges of the sidewalls that are distal the web.
The systems disclosed by Paquette U.S. Pat. No. 5,127,203 and Brady U.S. Pat. No. 5,127,760 each include an upper channel member having screw receiving slots in its sidewalls. The upper ends of the studs are positioned within the upper channel member between a pair of opposed slots, such as shown by FIG. 1 of Brady U.S. Pat. No. 5,127,760. The upper channel members are typically provided with a large number of slots so that there is a large number of places to secure the studs to the upper frame member. Consequently, most of the slots in the upper channel member remain unused in a given application. Although they are unused, they still require a cost to make, and there presence acts to weaken the upper channel member.
In the systems disclosed by Paquette U.S. Pat. No. 5,127,203 and Brady U.S. Pat. No. 5,127,760, the slots in the upper channel members are outside of the upper end portions of the studs. Sheet-metal screw fasteners extend through the slots and are screwed into the sidewalls of the upper ends of the studs. The screws are intended to slide in the slots during vertical movement of the studs relative to the upper frame members. When the screws are tightened too much, which happen often, the studs are clamped between the heads of the screw fasteners and the upper end portions of the studs. This clamping retards and often prevents movement, often causing damage to the wall structure.
De Framcesco et al. U.S. Pat. No. 5,685,121 discloses studs composed of telescopically connected upper and lower portions, making them costly to manufacture. The sidewalls of one of the end portions includes longitudinal slots. Screw fasteners extend through the sidewalls of the other end portion and extend into the slots. The upper end portion fits snugly within the downwardly extending channel space of the upper frame member. The upper end of the upper end portion extends upwardly to the web of the upper frame member.
An object of the present invention is to provide a system which obviates the high cost of manufacturing the upper channel member and maintains the studs free for vertical movement relative to the upper channel member. Another object of the invention is to provide a system in which the placement of the studs is not limited to the location of preformed slots in the sidewalls of the upper channel member, but rather the studs can be placed at any location along the upper channel member and then be connected to the upper channel member at that location and remain free to move vertically relative to the upper channel member.
An object of the present invention is to provide a simplified framing system in which the studs and the upper and lower channel members are all relatively inexpensive to manufacture, and the screw fasteners used to secure the studs to the channel members can be tightened without causing the sidewalls of the upper channel member to be clamped between the sidewalls of the studs and the heads of the screw fasteners.